CookieManager.java

package org.lodder.subtools.sublibrary.util.http;

import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.StringTokenizer;

/**
 * CookieManager is a simple utilty for handling cookies when working with java.net.URL and
 * java.net.URLConnection objects.
 * 
 * 
 * Cookiemanager cm = new CookieManager(); URL url = new
 * URL("http://www.hccp.org/test/cookieTest.jsp");
 * 
 * . . .
 * 
 * // getting cookies: URLConnection conn = url.openConnection(); conn.connect();
 * 
 * // setting cookies cm.storeCookies(conn); cm.setCookies(url.openConnection());
 * 
 * @author Ian Brown
 * 
 **/

public class CookieManager {

  private Map<String, Map<String, Map<String, String>>> store;

  private static final String SET_COOKIE = "Set-Cookie";
  private static final String COOKIE_VALUE_DELIMITER = ";";
  private static final String PATH = "path";
  private static final String EXPIRES = "expires";
  private static final String DATE_FORMAT = "EEE, dd-MMM-yyyy hh:mm:ss z";
  private static final String SET_COOKIE_SEPARATOR = "; ";
  private static final String COOKIE = "Cookie";

  private static final char NAME_VALUE_SEPARATOR = '=';
  private static final char DOT = '.';

  private DateFormat dateFormat;

  public CookieManager() {
    store = new HashMap<String, Map<String, Map<String, String>>>();
    dateFormat = new SimpleDateFormat(DATE_FORMAT);
  }

  /**
   * Retrieves and stores cookies returned by the host on the other side of the the open
   * java.net.URLConnection.
   * 
   * The connection MUST have been opened using the connect() method or a IOException will be
   * thrown.
   * 
   * @param conn a java.net.URLConnection - must be open, or IOException will be thrown
   * @throws java.io.IOException Thrown if conn is not open.
   */
  public void storeCookies(URLConnection conn) throws IOException {

    // let's determine the domain from where these cookies are being sent
    String domain = getDomainFromHost(conn.getURL().getHost());

    Map<String, Map<String, String>> domainStore; // this is where we will store cookies for this
                                                  // domain

    // now let's check the store to see if we have an entry for this domain
    if (store.containsKey(domain)) {
      // we do, so lets retrieve it from the store
      domainStore = store.get(domain);
    } else {
      // we don't, so let's create it and put it in the store
      domainStore = new HashMap<String, Map<String, String>>();
      store.put(domain, domainStore);
    }

    // OK, now we are ready to get the cookies out of the URLConnection

    String headerName = null;
    for (int i = 1; (headerName = conn.getHeaderFieldKey(i)) != null; i++) {
      if (headerName.equalsIgnoreCase(SET_COOKIE)) {
        Map<String, String> cookie = new HashMap<String, String>();
        StringTokenizer st = new StringTokenizer(conn.getHeaderField(i), COOKIE_VALUE_DELIMITER);

        // the specification dictates that the first name/value pair
        // in the string is the cookie name and value, so let's handle
        // them as a special case:

        if (st.hasMoreTokens()) {
          String token = st.nextToken();
          String name = token.substring(0, token.indexOf(NAME_VALUE_SEPARATOR));
          String value = token.substring(token.indexOf(NAME_VALUE_SEPARATOR) + 1, token.length());
          domainStore.put(name, cookie);
          cookie.put(name, value);
        }

        while (st.hasMoreTokens()) {
          String token = st.nextToken();
          cookie.put(token.substring(0, token.indexOf(NAME_VALUE_SEPARATOR)).toLowerCase(),
              token.substring(token.indexOf(NAME_VALUE_SEPARATOR) + 1, token.length()));
        }
      }
    }
  }

  /**
   * Prior to opening a URLConnection, calling this method will set all unexpired cookies that match
   * the path or subpaths for thi underlying URL
   * 
   * The connection MUST NOT have been opened method or an IOException will be thrown.
   * 
   * @param conn a java.net.URLConnection - must NOT be open, or IOException will be thrown
   * @throws java.io.IOException Thrown if conn has already been opened.
   */
  public void setCookies(URLConnection conn) throws IOException {

    // let's determine the domain and path to retrieve the appropriate
    // cookies
    URL url = conn.getURL();
    String domain = getDomainFromHost(url.getHost());
    String path = url.getPath();

    Map<String, Map<String, String>> domainStore = store.get(domain);
    if (domainStore == null) return;
    StringBuffer cookieStringBuffer = new StringBuffer();

    for (Entry<String, Map<String, String>> entry : domainStore.entrySet()) {
      Map<String, String> cookie = entry.getValue();
      // check cookie to ensure path matches and cookie is not expired
      // if all is cool, add cookie to header string
      if (comparePaths((String) cookie.get(PATH), path)
          && isNotExpired((String) cookie.get(EXPIRES))) {
        if (cookieStringBuffer.length() > 0) cookieStringBuffer.append(SET_COOKIE_SEPARATOR);

        cookieStringBuffer.append(entry.getKey());
        cookieStringBuffer.append("=");
        cookieStringBuffer.append((String) cookie.get(entry.getKey()));
      }
    }

    try {
      conn.setRequestProperty(COOKIE, cookieStringBuffer.toString());
    } catch (java.lang.IllegalStateException ise) {
      throw new IOException(
          "Illegal State! Cookies cannot be set on a URLConnection that is already connected. "
              + "Only call setCookies(java.net.URLConnection) AFTER calling java.net.URLConnection.connect().");
    }
  }

  private String getDomainFromHost(String host) {
    if (host.indexOf(DOT) != host.lastIndexOf(DOT)) {
      return host.substring(host.indexOf(DOT) + 1);
    } else {
      return host;
    }
  }

  private boolean isNotExpired(String cookieExpires) {
    if (cookieExpires == null) return true;
    Date now = new Date();
    try {
      return (now.compareTo(dateFormat.parse(cookieExpires))) <= 0;
    } catch (java.text.ParseException pe) {
      pe.printStackTrace();
      return false;
    }
  }

  private boolean comparePaths(String cookiePath, String targetPath) {
    if (cookiePath == null) {
      return true;
    } else if (cookiePath.equals("/")) {
      return true;
    } else
      return targetPath.regionMatches(0, cookiePath, 0, cookiePath.length());

  }

  /**
   * Returns a string representation of stored cookies organized by domain.
   */

  public String toString() {
    return store.toString();
  }
}